Contrast sensitivity--an unnoticed factor of visual perception in children with developmental delay: normal data of the Cambridge Low Contrast Gratings test in children.

Contrast sensitivity is one of several factors necessary to obtain good visual quality. The aim of this study was to develop normal data on the Cambridge Low Contrast Gratings test in children and to compare these data with data from a group of children with developmental delay. Ninety-nine normal children (aged 2-14 years) and 146 children with developmental delay were tested with the contrast sensitivity test. All children had normal visual acuity and stereopsis. The normal children had an age-dependent development in contrast sensitivity, and adult level was reached after the age of 10 years. A significantly lower score was found in children with developmental delay compared to normal children. The Cambridge Low Contrast Gratings test is suitable for preschool children and children with developmental delay because of its simplicity, and it might be a valuable tool in diagnosing ophthalmologic diseases in children with developmental delay.